1. Field of the Invention
The present invention relates to a wired circuit board assembly sheet in which a plurality of wired circuit boards are formed.
2. Description of Related Art
A wired circuit board typically comprises an insulating base layer, a conductive pattern formed on the insulating base layer, and an insulating cover layer formed on the insulating base layer to cover the conductive pattern. Such a wired circuit board is produced as a wired circuit board assembly sheet in which, e.g., a plurality of wired circuit boards are formed on a single metal supporting board.
More specifically, in the production of the wired circuit board assembly sheet, the insulating base layer, the conductive pattern, and the insulating cover layer are successively formed in an aligned state on the single metal supporting board to correspond to each of the individual wired circuit boards. Then, the metal supporting board is partially cut out such that the cut-out portion corresponds to an outer shape of each wired circuit board, whereby each of the wired circuit boards and the supporting sheet for supporting each wired circuit board are formed. In this manner, the wired circuit boards are produced as the wired circuit board assembly sheet in which the plurality of wired circuit boards are provided in an aligned state on the single metal supporting board.
Then, each of the wired circuit boards is appropriately cut away from the wired circuit board assembly sheet described above for wide use in various electric equipment and electronic equipment.
In such a wired circuit board assembly sheet, it has been known to provide a defectiveness distinguishing mark corresponding to each wired circuit board for distinguishing defectiveness.
For example, it has been proposed to distinguish whether a circuit board is defective or not by removing an alignment mark serving as a reference for aligning an electronic component or the like with laser processing to recognize the presence or absence of the alignment mark using an automatic image recognition device (see, e.g., Japanese Unexamined Patent Publication No. 2001-127399).